1. Field of the Invention
The present invention relates generally to flexible circuit connectors and, more particularly, to high density connectors of that type which apply a progressive contact wiping action as the mating members are moved toward closure.
2. Description of the Prior Art
The present invention is an improvement resulting from a continuing investigation of the potential application of flexible circuit technology as a solution to high density interconnect with enhanced electrical characteristics. As is customary in the art, the term "flex circuit" and its derivations will hereinafter be used in place of the term "flexible circuit" and its derivations.
The increasing demand for higher speeds in digital processing is dictating requirements for card edge connectors that currently cannot be met by commercially available components in terms of I/O density and electrical signal integrity. Conventional connectors using metal pin and spring beam contacts cannot easily be miniaturized to satisfy the anticipated pin count densities for future high performance computers and the inherent electrical characteristics cannot be readily adjusted to meet requirements in terms of propagation delay, risetime degradation, reflection and crosstalk.
The inherent features of flex circuit technology and its artwork driven manufacture permits the custom design of signal line characteristics. The ability to manufacture this material to precise tolerances with mechanically formed or photo-etched contact features makes it an ideal component on which to base the design of a state-of-the-art high performance connector.
Typically of known but recent connection constructions between flex circuits effected in a non-wiping fashion is U.S. Pat. No. 4,913,656 to Gordon et al. Another recent construction is disclosed in U.S. Pat. No. 4,911,643 to Perry et al. which provides a high density connector having a spring element in the form of an elongated hollow split tube with a heat-recoverable member of shape-memory alloy positioned within the tube. First and second sets of parallel spaced conductors terminate at least at one end of the tube in a first and second matrix of contact pads, the matrices and the pads being positioned within the split. A change in temperature changes the shape-memory alloy from one metallurgical state to another, causing movement of the heat-recoverable member and the spring means to open and close the connector.
Flexible circuit connectors or the like which employ elastomer or resilient members to increase contact pressure are disclosed, for example, in U.S. Pat. No. 4,834,660 to Cotti; U.S. Pat. No. 4,798,541 to Porter; U.S. Pat. No. 4,717,345 to Gordon et al; U.S. Pat. No. 4,693,530 to Stillie et al; and U.S. Pat. No. 4,693,529 to Stillie. Of these, Gordon et al. '345 and Cotti '660 disclose resilient members which provide contact wiping action. Also, in a number of the embodiments disclosed in the Gordon et al. '345 patent, alignment pins are employed to retain the relative relationship of the mating contact supports as they are moved between withdrawn and engaged positions. A circuit connector for joining flexible circuits to a PCB which applies a wiping action as connection is begun, then completed, is disclosed in U.S. Pat. No. 4,871,315 to Noschese.
U.S. Pat. No. 2,869,043 to Locher discloses connector having an alignment pin which simultaneously aligns the mating components and serves as an electrical conductor.
It was with knowledge of the state of the art as exemplified by the foregoing patents that the present invention has been conceived and is now reduced to practice.